The relationship between the date of river entry and the estimated spawning position of adult Atlantic salmon (Salmo salar L.) in two major Scottish east coast rivers
adult, Atlantic salmon, migration, monitoring, Salmo salar, salmon, Scotland, spawning, telemetry
Wildlife Telemetry: Remote Monitoring and Tracking of Animals
Priede IG;Swift SM;
In Scotland, adult Atlantic salmon (Salmo salar L.) enter the major east coast salmon rivers throughout most of the year (Calderwood 1922, Shearer 1990) although they spawn during a relatively short period in the autumn. Shearer (1990) shows that the timing of the return migration of adult Atlantic salmon (fish which have spent more than one winter at sea before returning to spawn) and grilse (one sea-winter fish) to the River North Esk is highly structured. Not only do the majority of older sea-age salmon return earlier, but within any given sea-age class the older river-age fish also tend to enter the river earlier in the season. Radio-tracking studies were carried out on two major east coast Scottish rivers, the Aberdeenshire Dee (between 1985 and 1989) and the Spey (1988 and 1989). This chapter examines how the timing of river entry is related to estimated spawning location for each sea-age class entering the river. We will also briefly consider implications for the management of salmon stocks.